President George Washington instituted a sophisticated seven-year crop rotation system in his fields to improve agricultural output. He probably learned this system of giving fields a rest from Torah parshat Behar, which we read this week. We can "glean" some important lessons for our lives from the same lines of Torah.

The key question is: what’s with seven? In Jewish thought, seven is a number of completion, because Genesis records God to create the world in six days and rest on the seventh. Torah maps its agricultural cycle to the cycle of creation: we farm the land for six years and give it a rest on the seventh. That same cycle applies to the ancient Jewish idea of commerce: debts were paid on a seven-year cycle, and indentured servants working off their debts went free in the seventh year.

We can joke about other sevens (e.g. baseball’s seventh-inning stretch), but resting after six –whether six hours, six days or six years – turns out to have inherent benefit to both individual and society. Fortune magazine reports that we are most productive in six hours of work (or 29 hours per week): after six, worker productivity then plateaus (we’re not productive in seven hours) and soon declines.

Rest, it turns out, is important if not a way to improve production. Farmers (and Torah) have long understood the limits of productivity; that depleting the land reduces its output. Yet our society fails to value rest. Motley Fool reports that taking a vacation can boost productivity at work, but a 2014 poll found that 78% of U.S. workers did not take all their paid vacation leave.

And how do we tend to use our non-working hours? Apparently we spend a lot of time in front of electronics and with bad consequences. A 2015 National Cancer Institute study of people 50 to 71 showed that persons who watched seven hours or more of television a day were 47 times more likely to have died during the study period! A 2010 Kaiser Foundation report said that a majority of children spend over seven hours in front of a screen. The American Academy of Pediatricians warns that excessive media use can lead to attention problems, school difficulties, sleep and eating disorders, and obesity. It might even be that seven of most anything except sleeping hours – seven hours of screen time, seven days of work, seven years of consecutive planting – is hardwired to be excessive in our lives.

So let’s get religious about honoring our sevens and giving activities a rest. It’s wise – and very Jewish – to do our best in and for the world by honoring our sevens. Give your brain and body the gift of activity rotations, just like Washington’s crop rotations and letting the land rest. Don't deplete yourselves, because your body is perhaps the most wondrous of God’s gifts.